Updated websocket example to improve clarity and to be more distinct from chat example

[alexpyattaev]

Motivation

The web sockets example was not looking nice, it was not user-friendly at all (took a while to figure out what it was even supposed to be able to do). Furthermore, it was not actually showcasing anything about web sockets that the chat example did not already demonstrate better. Either it had to go, or it had to be made more distinct, so I took the time to make it more "involved".

Solution

• all parts of the example have received additional comments
• the sample webpage has received hints that the user should open browser's console to see messages (it was just blank)
• added a Python script that demonstrates some more tricky features such as ping/pong handling, and allows to quickly connect with multiple "users" to the test server
• added the logic to push unsolicited messages to the client form the server (which is not obvious at all though easy to actually do)
• added comments explaining that one should not try to implement pong responder (as axum already has one builtin, and thus even though you can see the ping messages, you should not actually respond to them)

[davidpdrsn]

Thanks! I skimmed the changes and they generally look good. Will do a more thorough review later.

However we cannot merge Python code. I don't know Python so don't wanna take on maintenance of that. Can you write the client in Rust instead?

[alexpyattaev]

Well websocket client in Rust might be a bit more "fun" than I originally anticipated, but I can give it a try. Stay tuned.

[alexpyattaev]

All right, now there is a proper Rust client, which is properly illustrating the concurrency features of axum websockets.
Code-wise it is actually 90% identical to the server, which is pretty cute if someone wants to eventually have both sides of the socket in Rust.
Feel free to kill the Python client.py if you feel like it deserves it =)

[alexpyattaev]

Ok the fat trimming is done, I hope I have not missed anything.

[davidpdrsn]

Great! Almost there. Just a couple of minor nitpicks here and there.

[alexpyattaev]

Thanks for the tips! I've re-tested everything (there was a missing import and one unneeded import) and the last commit should contain a fully functional example with all your suggestions incorporated.

[alexpyattaev]

Bump =)

[davidpdrsn]

No need for bumps. We'll get to this when we get to it. I'm currently on Christmas holiday playing video games.

[davidpdrsn]

Thanks for working on this!

[alexpyattaev]

You are welcome! I quite like your standards of quality, gives me confidence using Axum in production.

[FrankReh]

I'm sure many people are going to benefit from this example, including the command-line client. Big thank you to both!

I was wondering how to run the example and then I saw the comments in main.rs (of course). Small nit, at least for me to get them running:

diff --git a/examples/websockets/src/main.rs b/examples/websockets/src/main.rs
index 26a31a2..6d598b1 100644
--- a/examples/websockets/src/main.rs
+++ b/examples/websockets/src/main.rs
@@ -3,13 +3,13 @@
 //! Run the server with
 //!
 //! ```not_rust
-//! cargo run -p example-websockets
+//! cargo run -p example-websockets --bin example-websockets
 //! firefox http://localhost:3000
 //! ```
 //!
 //! Alternatively you can run the rust client with
 //! ```not_rust
-//! cargo run -p example-client
+//! cargo run -p example-websockets --bin example-client
 //! ```

[davidpdrsn]

@FrankReh good catch! Wanna submit a PR?